@phdthesis{Ming2021, author = {Ming, Wenbo}, title = {Synthesis of α‑Aminoboronates and PBP Pincer Palladium Boryl Complexes}, doi = {10.25972/OPUS-19832}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198323}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The first Borono-Strecker reaction has been developed to synthesize α-aminoboronates via a multicomponent reaction of readily available carbonyl compounds (aldehydes and ketones), amines and B2pin2. The preparation of α-amino cyclic boronates can be achieved via multicomponent coupling of salicylaldehydes, amines, and B2(OH)4. In addition, the diazaborole-based PBP pincer palladium chloride and the diazaborole-based PBP pincer palladium trifluoromethanesulfonate complexes were synthesized and fully characterized for the first time, and used as catalysts for Suzuki-Miyaura cross-coupling reactions.}, language = {en} } @article{LiuMingLuoetal.2020, author = {Liu, Xiaocui and Ming, Wenbo and Luo, Xiaoling and Friedrich, Alexandra and Maier, Jan and Radius, Udo and Santos, Webster L. and Marder, Todd B.}, title = {Regio- and Stereoselective Synthesis of 1,1-Diborylalkenes via Br{\o}nsted Base-Catalyzed Mixed Diboration of Alkynyl Esters and Amides with BpinBdan}, series = {European Journal of Organic Chemistry}, volume = {2020}, journal = {European Journal of Organic Chemistry}, number = {13}, doi = {10.1002/ejoc.202000128}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214728}, pages = {1941 -- 1946}, year = {2020}, abstract = {The NaOtBu-catalyzed mixed 1,1-diboration of terminal alkynes using the unsymmetrical diboron reagent BpinBdan (pin = pinacolato; dan = 1,8-diaminonaphthalene) proceeds in a regio- and stereoselective fashion affording moderate to high yields of 1,1-diborylalkenes bearing orthogonal boron protecting groups. It is applicable to gram-scale synthesis without loss of yield or selectivity. The mixed 1,1-diborylalkene products can be utilized in Suzuki-Miyaura cross-coupling reactions which take place selectivly at the C-B site. DFT calculations suggest the NaOtBu-catalyzed mixed 1,1-diboration of alkynes occurs through deprotonation of the terminal alkyne, stepwise addition of BpinBdan to the terminal carbon followed by protonation with tBuOH. Experimentally observed selective formation of (Z)-diborylalkenes is supported by our theoretical studies.}, language = {en} } @article{LiuMingZhangetal.2019, author = {Liu, Xiaocui and Ming, Wenbo and Zhang, Yixiao and Friedrich, Alexandra and Marder, Todd B.}, title = {Copper-Catalyzed Triboration: Straightforward, Atom-Economical Synthesis of 1,1,1-Triborylalkanes from Terminal Alkynes and HBpin}, series = {Angewandte Chemie International Edition}, volume = {58}, journal = {Angewandte Chemie International Edition}, number = {52}, doi = {10.1002/anie.201909376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206185}, pages = {18923-18927}, year = {2019}, abstract = {A convenient and efficient one-step synthesis of 1,1,1-triborylalkanes was achieved via sequential dehydrogenative borylation and double hydroborations of terminal alkynes with HBpin (HBpin=pinacolborane) catalyzed by inexpensive and readily available Cu(OAc)\(_2\). This process proceeds under mild conditions, furnishing 1,1,1-tris(boronates) with wide substrate scope, excellent selectivity, and good functional-group tolerance, and is applicable to gram-scale synthesis without loss of yield. The 1,1,1-triborylalkanes can be used in the preparation of α-vinylboronates and borylated cyclic compounds, which are valuable but previously rare compounds. Different alkyl groups can be introduced stepwise via base-mediated deborylative alkylation to produce racemic tertiary alkyl boronates, which can be readily transformed into useful tertiary alcohols.}, language = {en} } @article{LiuMingFriedrichetal.2020, author = {Liu, Xiaocui and Ming, Wenbo and Friedrich, Alexandra and Kerner, Florian and Marder, Todd B.}, title = {Copper-Catalyzed Triboration of Terminal Alkynes Using B\(_2\)pin\(_2\): Efficient Synthesis of 1,1,2-Triborylalkenes}, series = {Angewandte Chemie International Edition}, volume = {59}, journal = {Angewandte Chemie International Edition}, number = {1}, doi = {10.1002/anie.201908466}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206694}, pages = {304-309}, year = {2020}, abstract = {We report herein the catalytic triboration of terminal alkynes with B\(_2\)pin\(_2\) (bis(pinacolato)diboron) using readily available Cu(OAc)\(_2\) and P\(^n\)Bu\(_3\). Various 1,1,2-triborylalkenes, a class of compounds that have been demonstrated to be potential matrix metalloproteinase (MMP-2) inhibitors, were obtained directly in moderate to good yields. The process features mild reaction conditions, a broad substrate scope, and good functional group tolerance. This copper-catalyzed reaction can be conducted on a gram scale to produce the corresponding 1,1,2-triborylalkenes in modest yields. The utility of these products was demonstrated by further transformations of the C-B bonds to prepare gem -dihaloborylalkenes (F, Cl, Br), monohaloborylalkenes (Cl, Br), and trans -diaryldiborylalkenes, which serve as important synthons and have previously been challenging to prepare.}, language = {en} }